Gaseous electric discharge device



May 26, 1936. K WIEGAN 2,042,136

GASEOUS ELECTRIC DISCHARGE DEVICE Filed March 25, 1935 INVENTOR cIiuwl? 91 S, M

RNEY

Patented May 26, 1936 UNITED STATES PATENT OFFICE Kurt Wiegand, Berlin-neu-Tempelhof, Germany,

assignor to General Electric Company, a corporation of New York Application March 25, 1935, Serial No. 12,926 In Germany March 29, 1934 1 Claim. (01. 176-124) The present invention relates to gaseous electrlc discharge devices generally and more particularly the invention relates to methods and means for facilitating the starting of such de- 5 vices.

It is advantageous to provide the thermionic electrodes of gaseous electric discharge devices with heaters, such as an electric resistance, to rapidly raise said electrodes to an electron emitting, discharge supporting temperature which facilitates the starting of the discharge in such devices. It is also advantageous to connect the electrode heaters in series through a resistance across the terminals of the current source and to provide automatic switch means, such as a time switch or a relay, to break the series connection between the heaters of the electrodes after the discharge between said electrodes has started to increase the efliciency of the device.

The object of the present invention is to provide a positive acting means for breaking the series connection between the electrode heaters in gaseous electric discharge devices of the above type. Still further objects and advantages attaching to the device and to its use and operation will be apparent to those skilled in the art from the following particular description.

The invention attains its objects by providing an auxiliary gaseous electric discharge device in the current lead connecting said electrode heaters in series. The starting and operating characteristics of the auxiliary device are such that when potential is applied to the heater circuit electrodes of the device to their electron emitting temperature. The prolific emission of electrons from the electrodes ionizes the gas in the container of the device and the discharge starts between said electrodes. As soon as the discharge in the main device starts the voltage across the electrodes of the auxiliary device drops below the maintaining voltage of the discharge therebetween and the discharge in said auxiliary device is extinguished which interrupts current flow through the heater circuit. The thermionic electrodes are maintained at an electron emitting temperature by the discharge incident thereat during the operation of the lamp device.

In the drawing accompanying and forming part of this specification two embodiments of the invention are shown, in which Fig. 1 is a schematic view of one embodiment of the invention, and

F g. 2 is a similar view of another embodiment of the invention.

Like numbers denote like parts in both the figures.

Referring to the Fig. 1 the new and novel apparatus comprises a gaseous electric discharge lamp device comprising a container I having an electric discharge conducting gaseous atmosphere therein, such as a rare -gas,-a metal vapor, or a mixture of gas and metal vapor, and a thermionic electrode 2, 3 sealed therein at each end thereof. Each of said electrodes 2, 3 comprises a heater filament 2, such as a tungsten filament, wrapped around a curved rod or bar 3 of electron emitting material, such as a pressed and sintered rod of a pulverized mixture of tungsten, barium oxide and strontium oxide. One of said electrodes 2, 3 is connected to a terminal 6 of an alternating current source by current lead 5 having a regulating resistance 4 connected therein. The other of said electrodes 2, 3 is connected to the other terminal I of said current source by the lead 8. The heater filaments 2 of said electrodes 2, 3 are connected in series by current lead 9 having a small resistance I3 and a glow lamp connected in series therein. Said glow lamp. comprises a container I having a gaseous atmosphere therein and a pair of electrodes III and II sealed therein. The high resistance I6, which is enclosed by an insulating tube I5, such as a glass tube, and has the ends I4 thereof projecting from said tube I5 and terminating adjacent the electrodes 2, 3, extends along the discharge path between said electrodes 2, 3. Said tube I5 is supported in said container I by a pair of spring rings II. The high resistance wire I6 facilitates the starting of the discharge between said electrodes 2, 3.

When potential is applied to the above described apparatus a glow discharge takes place between the electrodes I0 and I I of the glow lamp and current flows through the heater filaments 2 of the electrodes 2, 3. Said electrodes 2, 3 are rapidly heated to an electron emitting temperature by said heaters 2. When the gaseous filling in the container I is sufliciently ionized by the electrons emitted by the heated electrodes 2, 3 the discharge starts between said electrodes 2, 3. When the discharge starts in the main discharge device the voltage between the electrodes I0 and II of the glow lamp drops below that required to support a discharge therebetween and current flow through the heater circuit is interrupted. During the operation of the discharge between said electrodes 2, 3 these electrodes are maintained at an electron emitting temperature by the main, luminous discharge therebetween and by the glow discharge which takes place between each or said main electrodes 2, 3 and the respective end I4 oi! wire I6 adjacent thereto.

The embodiment of the invention illustrated in Fig. 2 of the drawing is the same as that illustrated inFig. 1 except that in this embodiment the glow lamp and the current lead 9 connecting the heater filaments 2 in series are sealed into the lamp container I. A pair of resistances I3 is sealed into the container I2 01 the glow lamp, each 01' said resistances being connected to one of said electrodes II) or II. When desired, said resistances I3 are mounted outside the glow lamp container I2, but inside said container I. A con-' ducting strip I8 is applied to the outer wall of said container I and extends along the discharge path between said electrodes 2, 3. Said strip I 8 is connected to the current lead 5. When desired, a conducting element, similar to the wire I6 of Fig. 1, is mounted inside the container I in place or the outer strip t8.

When the gaseous atmospherein the container I consists of a rare gas, such as neon the container I2 of the glow lamp is omitted, when desired, whiehsimplifies the structure of the apparatus. When the gaseous atmosphere comprises a metal vapor, such as mercury vapor, the further advantage is gained that the glow discharge between said electrodes I0 and II heats the metal vapor in the center 01' the container I to avoid condensation thereof at that part of the container.

When desired, the electrodes I0 and II are activated and the discharge therebetween is an arc discharge. An arc discharge requires a higher current and a lower voltage for its operation than a glow discharge. Whether a glow charge or an arc discharge is used in the series heater circuit depends therefor on the starting and operating characteristics '01 the main discharge between said electrodes 2, 3. 5

While I have shown and described and have pointed out in the annexed claim certain novel features of the invention, it will be understood that various omissions, substitutions and changes in the forms and details or the device illustrated 10 and in its use and operation may be made by those skilled in the art without departing from the broad spirit and scope or the invention, for example, different types 01 thermionic electrodes such as a metal filament coated or impregnated 15 with electron emitting material, or the well known Hull electrode, are used in place of the electrodes 2, 3 when desired.

What I claim as new and desire to secure by Letters Patent 01 the United States is:- v 20 In combination a gaseous electric discharge device comprising a container, electrodes sealed therein, a gaseous atmosphere therein, said electrodes comprising a heater element and an elecafter said first named device has started.

KURT WIEGAND. 

